In the following discussion certain articles and methods will be described for background and introductory purposes. Nothing contained herein is to be construed as an “admission” of prior art. Applicant expressly reserves the right to demonstrate, where appropriate, that the articles and methods referenced herein do not constitute prior art under the applicable statutory provisions.
There are many scientific and industrial arrangements and processes that involve the introduction of fairly precise amounts of one or more substances into a container. Depending on various factors such as the nature of the substance introduced, the construction and properties of the container, as well as the technique used to introduce these substances, it is a common occurrence that some of a substance introduced into the container sticks to the walls of the container in a manner that prevents it from being combined and/or interacting with other substances in the container. When the nature of the process calls for precise amounts of the various substances to be combined, the above-described “sticking” problem can have a significant and undesirable impact on the desired outcome of the process.
In addition, while automation is desirable in the introduction of substances, it can prove difficult to precisely deliver small quantities of substances. Thus, when precise amounts of substances are called for, it is a common practice to measure and introduce these substances into a container by hand. This labor intensive procedure is clearly less than ideal from an efficiency stand point.
One example of the type of scientific or industrial process referred to above is the isolation and/or separation of biological components from a sample. One way of accomplishing this isolation and/or separation involves introducing a biological sample, magnetizable particles, and possibly other substances into a tube, usually gravimetrically or via a pipette. One or more of the biological components present in the tube become associated with the magnetizable particles. Magnets are then caused to come into close proximity to the tube wall(s) causing the magnetizable particles, with the biological component(s) attached thereto, to be drawn to the wall(s) of the tube. The remainder of the constituents present in the tube can then be removed, thereby separating the biological component(s). Various further process steps can be employed to achieve a desired objective.
The walls of the tube and the pipette tip often possess a surface charge that can attract substances thereto. Thus, for example, the introduction of magnetizable particles into the tube poses the above-described problem in that they can often stick to the walls of the tube or pipette in a way that prevents them from properly associating themselves with the rest of the constituents in the tube. Moreover, even if care is taken to prevent the sticking problem when the particles are first introduced, subsequent movement of the tube with the particles contained therein can cause the particles to be thrown against, and stick to, the walls of the tube. Since processes such as the one described above often involve small sample sizes and/or rely upon precise amounts of the various substances to mix together in order to produce a desirable or accurate result, the sticking phenomenon poses a significant problem in the accuracy and reliability in such isolation and/or separation techniques.
Therefore, there is a need in the art, in general to provide arrangements and methods that facilitate more accurate introduction and association of substances within a container. There is also a need in the art for arrangements and methods that promote more accurate and efficient introduction and association of substances involved in the isolation and/or separation of biological components from a sample.